SHANGHAI, CHINA – GE’s Marine Solutions and Dalian Shipbuilding Industry Co. Ltd. (DSIC) completed a preliminary design for the conversion of a steam turbine powered LNG Carrier (LNGC) to a gas turbine-based propulsion system. The study aims at steam powered LNGCs that offer low fuel efficiency but are not ready to be retired from service. The new design will feature GE’s reliable and compact COmbined Gas turbine, Electric and Steam (COGES) system.

“We are delighted to work with the DSIC team to develop this new concept of a LNGC power system conversion,” said GE’s Brien Bolsinger, Vice President, Marine Operations, Evendale, Ohio, USA. “This feasibility study provides ship owners a competitive retrofit solution for 10 to 15 year-old steam-powered LNG carriers,” Bolsinger added.

According to Yingbin Ma, DSIC Deputy Technical Director, “A gas turbine’s smaller footprint allows for the minimum necessary conversion work required by the shipyard. By converting to a COGES power system, the fuel efficiency of the ship will be improved by 30%. This allows ship owners to increase the charter rate and win back opportunities in a market dominated by dual-fuel diesel engines. This study achievement is based on a 138,000 cubic meter LNGC powered by a steam turbine, but it can be applied on other similar size ships.”

Figure 1 shows the typical configuration for an LNGC retrofit with a GE COGES system. The steam generators and its auxiliary system will be kept to produce steam for power generation. This re-use of equipment helps reduce the total investment of the conversion. The existing diesel generator on the original ship will remain as the backup for the electric power system.

Shown in Figure 2 is the gas turbine generator (GTG) that sits on the third platform, while the steam turbine generators (STG) remain on the second platform. Thanks to the small footprint of the gas turbine, neither the engine casing nor the crew accommodations area need to be removed, which is inevitable if a larger sized diesel engine were to be installed.

Benefits of Gas Turbines

Derived from GE’s CF6 family of aircraft engine, GE’s LM2500 family of aeroderivative gas turbines share the same proven jet engine technology with a field reliability of 99.9%. The LM2500 family includes the base LM2500 model (25 MW), LM2500+ (30 MW) and LM2500+G4 (35 MW). These same gas turbines are used onboard cruise ships, high speed yachts, fast ferries and offshore platforms, as well as by 35 navies worldwide. Three sizes of LM2500 gas turbines offer the flexibility to adapt the COGES power to a specific ship size and the ability to optimize performance. Equipped with a dry low emissions (DLE) combustor or a single annular combustor (SAC), a gas turbine can reduce nitrogen oxide (NOx) emissions to meet IMO Tier III/United States Environmental Protection Agency Tier IV requirements with no post combustion exhaust treatment.

Compared with two-stroke diesel engines, a gas turbine is 80% lighter and 30% smaller. Featuring reduced weight, size -- and using one of the existing steam turbines -- COGES offers a simpler conversion that requires less dry dock time compared to a similar conversion with diesel engines.

GE’s marine gas turbine business is part of GE Aviation and is headquartered in Cincinnati, Ohio. GE is one of the world’s leading manufacturers of marine propulsion products, systems and solutions including aeroderivative gas turbines ranging from 6,000 to 70,275 shaft horsepower/4.5 to 52 megawatts. These gas turbines reliably operate the world over in some of the most arduous conditions in temperatures ranging from -40 to 120 degrees F/-40 to 48 degrees C. For more information, visit ge.com/marine

About Dalian Shipbuilding Industry Co. Ltd.

Dalian Shipbuilding Industry Co. Ltd. (DSIC) was established in 1898. She is the biggest shipbuilding yard with the most comprehensive range of various products in China. Main businesses include shipbuilding, offshore engineering and construction, ship repair conversion recycling and heavy industry.

Share this

GE Aviation

GE Aviation is a world-leading provider of commercial, military and business and general aviation jet and turboprop engines and components as well as avionics, electrical power and mechanical systems for aircraft. GE has a global service network to support these offerings. GE and its customers are also working together to unlock new opportunities to grow and deliver more productivity beyond traditional services. GE Aviation is becoming a digital industrial business with its ability to harness large streams of data that are providing incredible insights and in turn, real operational value for customers.